Portable blackboard renovator



June 16, 1931. BENNINGTON 1,810,336

PORTABLE BLACKBOARD RENOVATOR Filed July 9, 1928 6 Sheets-Sheet 1 June 16, 1931. A BENNINGTON 1,810,336

PORTABLE BLACKBOARD RENOVATOR Filed July 9, 1928 6 Sheets-Sheet 2 zwrzwroz MZZWW J1me 1931- A. BENNINGTON PORTABLE BLACKBOARD RENOVATOR Filed July 9, 1928 6 Sheets-Sheet 5 June 16, 1931. BENNINGTQN 1310,1336

PORTABLE BLACKBOARD RENOVATOR Filed July 9, 1928 6 Sheets-Sheet 6 I I z a is! Patented June. 16, 1931 STAT as ALBERT BENNIN GTON, OF RIiDLEY PAR-K, PENNSYLVANIA PORTABLE BLACKBOARD RENGVATOR Application filed July 9,

v Myinvention relates to new and'useful improvements in a portable blackboard renovator, and has for one of itsobjects to V vary or improve the construction of a simi- 15 lar device illustrated in my. Patent No. 1,582,664, dated April 27, 1926, and the clean ing heads illustrated in Patents Nos. 1,623,520 and-1,623,521, dated April 5, 192?.

Another object of my invention is to'pro-' videpa cleaning head wherein the abraslve surfaces travel parallel with theaxes 0 they supporting mediums.

Another object of the invention is to pro-- vide two abrasive surfaces, the effective por- 15 tions of which are in parallelism and moving toward each other in order to overcome the tendencyto travel along the surface beingcleaned as occurs when but a single IBQ:

volving [abrasive surface is used. By overthe operator is greatly reduced.

Another "object of the invention is to provide a cleaning head comprising a suitable 25 casing in which are mounteda pair of revsive material, said rollers being arranged in parallelism and having means in one por-f vtion or compartment of the casing for'revolv-' ing saidv .rollers inunison in opposite directions so that the r effective working faces are movlngtoward each other.

. A further object of the lnvention is to pro vide'a simple, effective and improved means for detaohably or temporarily securing sheets of abrasive material on the rollers. U

A further object of the invention is to provide a blackboard. renovating machine comprising alcleaning. head including abrasive coming this tendencyto travel, the labor of oluble rollers for the reception of abra-- T and possibly portions of the blackboard sur-' stand how to use and makethe same, I will 1928. Serial No. 291,187.

board renovator constructed in accordance with my improvements, portions of which are broken away and shown in section to illustrate certaindetails. V

Fig. 2 is a plan view thereof. Fig. 3 is an end view of the Y-shaped' union through which the motor shaft and the refuse conduit are connected with the cleaning head.

Fig. 4 is a'plan View thereof showing a part of the motor to which it is connected.

Fig.5 is a side elevation of Fig.4.

Fig. dis a longitudinal sectional view there of with parts left in elevation.

Fig. 7 isan end view opposite tothat shown in Fig. 3'.

Fig. 8 isan enlarged view of the head with the closure plate or cover removed. 1OFigfi) is a section on the line 99 of Fig.

p ig. 10 is a section on the line 1010 of Fig.' 8, with the shafts and gearing left in elevation. 1 Y

Fig. 11 is a sectionon the line 1111 of Fig. 10. p i 80 Fig. 12 isa view looking into the mouth of the cleaning head with one of the rolls and component parts partlybroken away to illustrate structural .details.

Fig.1?) is an endview of one of the rollers carrying the abrasive substance and illustrating the manner in which the sheet of abrasive material is held in place.-

Fig. 14: is a similar view with the clamping rod removed. I i

Fig. 15 is an end view of the cleaning head opposite to that illustrated in Fig. 8.

for the apparatus and by which it may be 9 movedabout from place to place as the work progresses and on this base support is mount- 2 ed a tubular standard 21 for the reception of the extensionrod 22 which telescopes in the member 011 op f theextension rod 22 is mounted a table 23 to support a motor 24.

The table is also provided with a bracket 25 and to this is fastened the suction device 26 herein illustrated as a suction fan which is driven from the motor through the medium of a belt 27 running over a pulley 28 on the fan shaft and another pulley 29 on one end of the motor shaft.

The suction device discharges. through the outlet or exhaust 30 from which it may be directed to any desirable place of disposal for the solid particles as to a bag 31 removably mounted upon the exhaust or outlet.

To the inlet of the suction device is connected one end of a conduit 32, the other end of said conduit being attached to the branch 33 of the Y-shaped union or fitting 34, while the otherbranch 35 of said union is clamped about the bushing 36 surrounding the outer end ofthe motor shaft 37 as plainly shown in Fig. 6. Both of the branches 33 and 35 extend from the body 38 of the Y-shaped coupling and to said body is attached one end of the flexible tube or conduit 39 which in turn is connected 'at its outer free end with the cleaning head 40 to'be presently described.

In order to support the flexible conduit 39 and component parts adjacent its point of connection with the Y-shaped union so as to reduce to a minimum the possibility of the parts being damaged or broken, I provide a hanger 41 which is carried by or attached to the motor or some other suitable rigid portion of the machine and this hanger extends out a desirable distance beyond the connection between the conduit 39 and the Y-shaped union where it may be provided with a hook 42 for the reception of one end of an elastic or resilient suspending member 43, such as a spring, while the other end is attached to the conduit 39.

To the outer end of the motor shaft 37 is connected one end of a flexible shaft 44 inany suitable or well-known manner and said flexible shaft passes through the branch 35 and the body 38 of the Y-shaped union and then through the flexible conduit 39 and has a tubular connector 44 thereon for detachable connection with a shaft splice for coaction with the stub shaft splice 56 and the complete shaft thus formed is journalled in suitable ball bearings 57 and 58 carried by the barrel 59'set between the ribs 60 projecting from the inner surface of the neck 61 of the casing 62 to be hereinafter more fully described. The tubular connector 44 has an external groove 44 which acts as a conveyor to urge any material outward that might otherwise tend to enter the bearings.

Y The flexible shaft is generally enclosed in a flexible lattice-like sheath 63, Fig. 6, and said sheath is provided with a tubular terminal 64, Fig. 10, detachably connected with the reducing coupling 65 which in turn is detachably connected with the inner end of the casing sections.

barrel 59 and the other end of said sheath is connected to the bushing 36, Fig. 6.

The cleaning head casing 62 is divided transversely into a primary section 66 with which the neck 61 is formed and a secondary detachable section 67, the latter being held on the former by the screws 68 having threaded connection with the thick end wall and also by screws 69 having threaded connection with flanges 7 0 and 71 formed with the sections 66 and 67 respectively at the opposite end.

The interior of the cleaning head casing is divided into two main compartments, the larger one of which is represented by the numeral 72 and will be known as the roller compartment, while the other compartment 73 holds a train of gears and as will be obvious these compartments are formed by both of the sections 66 and 67.

In the roller compartment are located in parallel relation two rollers 74 and -75 mounted on shafts 76 and 77 respectively journalled in suitable ball bearings, indicated in dotted lines in the several views which are recessed in the thick end wall of the cleaning head casing and the flanges formed with the On the roller shafts are fixed gears 78 and 79, the former meshing with a gear 80 while the latter meshes with an idler gear 81 also meshing with the gear 79.

The gears 80 and 81 are mounted on suitableshafts 82 and 83 respectively which are suitably journalled, the shaft 82 being shown as journalled in ball bearings 84 and 85 recessed'in an enlargement or rib 86 through which said shaft 82 passes, said rib being located on the longitudinal center line of the cleaning head casing.

The shaft 82, on the outer end of which is mounted the gear 80, has a bevel gear 87 mounted on its inner end and meshing with a bevel gear 88 mounted on the stub shaft splice 56.

The upper end of the barrel 59 and the contiguous end of the rib86 are normally closed by a removable cap 89 in order to exclude foreign matter from the gears and bearings and the gear compartment 7 3 is normally closed by a closure plate 90 held in place by screws 91.

From the above, it will be obvious that when the flexible shaft 44 is revolved in the proper direction, motion will be transmitted through the gears 88 and 87 and the shaft 82 of the latter to the train of gears at one end of the cleaning head casing and through them to the rollers 74 and 75 so that said rollers will be revolved in opposite directions. and their outer working surfaces revolved toward each other so that during use of the device, the motion of one roller tends to counter-balance that of the other making it much easier for the operator to handle the cleaning head and hold it in any one place or move it about as desired.

7 and the walls of the rollerforming the tapered hole and in actual practice, it has been found that as the tapered pin is inserted, the abrasive sheet is drawn taut about the periphery of the roller.

In order to hold the. tapered pin in place and also draw it into its final position, said pin is provided with a head 96 in the form of a plate which may be secured to the larger end of the pin by a screw 97 and the ends of said plate 96 are provided with apertures for the reception of screws 98 which are threaded into the roller on both sides of the slot and as they draw said plate into the recess 99, the pin 95will be forced into the tapered hole.

In order to have access to the screws 98 and to permit the removal and replacement of the tapered pin without having to disassemble the parts of the cleaning head, the flange end wall of the section 67 is provided with recesses 100 in its upper edge with which the pins and their heads may align when the rollers are rotated to the proper positions.

In operation, when-the motor 24 is running the suction device 26 will produce a current of air through the tube or conduit 39 and the cleaning head, and at the same time the flexible shaft will be revolved for transmitting power and motion to therollers carrying the abrasive material. By moving the cleaning head with the rollers, or more particularly the abrasive material thereon, in contacting with a blackboard surface, the foreign ma terial such as the accumulation of grease will be ground away and since the rollers are revolved toward each other, the tendency will be to throw the particles dislodged from the blackboard surface into the cleaning head between said rollers where they will be transported by the current of air through'the conduits 39 to the Y-shaped union 3% and thence through the branch 33 of saidunion to the conduit 32 and through the latter and the i than would be the case if the head had to be always held in oneposition. This makes it possible to machineclean a greater area of the-blackboard and reduces the hand opera- 7 tion to a considerable'extent; r

0f courseI do not wish to be limited to the exact details of construction as herein shown, 7

as these may be varied *within the limits of the appended claims without departing from the spirit of my invention.

'Having thus fully described my invention, what I claim as new and useful is V 1. In a device of the character described, a cleaning head having a large and small compartment therein, aneck formed with the head, a sleeve swiveled to the neck, a-spllt,

shaft'mounted, in the neck,.a flexible shaft positioned in the sleeve andremovably connected tov the split shaft,a beveled gear carried by the upper endof the split shaft, a second beveled gear meshing with the first named beveled gear,'a driving shaft upon whichzthe second named beveled gearis secured, a driving gear secured upon said driv- I ing shaft and located within the small compartment of the cleaning head, a driven gear wheel meshing. withthe driving gear: wheel, a shaft upon which the driven: gear wheelsis mounted, an abrasive roll mounted upon said shaft within the large compartment, a second shaft j ournalled in the head, a second abrasive rolls in reverse directions, a neck formed with the head, a sleeve with which said neck is swivelly connected, ribs formed upon the inner surfa cc of the neck, a barrel positioned between said ribs, astub shaft ournalled in the barrel, a splice shaft coacting with the stub shaft for providing a slipped action, a beveled gear carried by the upper end of the stub shaft, a second beveled gear meshing with the first named beveled gear, a driving shaft upon which the second named beveled gear is;

mounted, said driving sh aft having mounted upon its outer end the driving gearof said train of gears, means for revolving the splice shaft, and means for sucking air from the large compartment.

3. In a device of the character described, a 120 1 cleaning head having a large and a small compartment therein, a neck formed wlth the head, a hollow enlargement having one end adjacentto the inner end of the neck and communicating with the smaller compartment. a barrel of smaller diameter than the neck and mounted therein, means common to the barrel and hollow enlargement for closing the space between said neck and hollow enlargement whereby an enclosed communi= cation is formed between-the barrel and hollow enlargement, a pair of abrasive rolls mounted in the larger compartment, a train of gears mounted in the smaller compartment adapted to revolve the rolls in reverse direc tions, a prime mover, mechanism for transmitting motion from said prime mover t0 the train of gears, a portion of said means being located in the barrel and the hollow enlargement, a suction device driven by the prime mover, and means to connect said suction device with the neck of the cleaning head for drawing material dislodged by the rolls from the larger compartment through the neck.

4. A device of the kind described including a head having two compartments, a neck formed with said head and communicating with one of the compartments therein, means to provide an enclosed passage-Way through the neck and the compartment with which said neck communicates to the other compartment in said head, a pair of rollers journalled in the compartment with which the neck communicates, a train of gears mounted in the other compartment for revolving said rollers in reverse directions, and mechanism in the enclosed passage-way for transmitting mo tion from a prime mover to the train of gears.

In testimony whereof, I have hereunto affixed my signature.

ALBERT BENNINGTON. 

